Efficacy and safety of lumbar epidural dexamethasone versus methylprednisolone in the treatment of lumbar radiculopathy: a comparison of soluble versus particulate steroids.

INTRODUCTION The literature is limited in the comparative efficacy and safety of dexamethasone phosphate (DP) compared with methylprednisolone acetate (MPA) in the treatment of lumbar radiculopathy by epidural injection. This study attempts to test the hypothesis that 2 corticosteroids are equivalent in efficacy and side effects. METHODS Patients with lumbar radicular symptoms for at least 6 months were randomized to equipotent doses of MPA 80 mg or DP 15 mg by lumbar translaminar epidurals administered under fluoroscopy. The epidurals were administered by different nonblinded practitioners other than the authors. Preprocedure Visual Analog Scale (VAS) pain scores by preoperative pain clinic nursing staff not involved in the study. On follow-up for the second epidural at 1 to 2 months, VAS scores and any reports of adverse side effects were obtained by pain clinic nursing staff who were blinded to the type of corticosteroid used. Electronic records were also reviewed for intervening changes in medication, additional therapeutic modalities, emergency room visits, and any other complications missed on nursing follow-up. RESULTS There were no significant demographic differences between the DP group (N = 30) and MPA group (N = 30). The mean days to follow-up was less for the DP group (41.1) versus the MPA group (51.1), although the difference was not statistically significant (P = 0.4284). Comparing the DP group and MPA group, there was a smaller mean decrease in VAS for the DP group (-19.7%) versus the MPA group (-27.2%), although the difference was not statistically significant (P = 0.3672). Eighty-seven percent of patients in the MPA group and 90% in the DP group had decreases in postprocedure VAS with no statistically significant difference between the 2 groups (P = 0.999). Thirteen percent of the MPA group and 10% of the DP group had increases in postprocedure VAS with no significant difference between the 2 groups (P = 0.999). The percentage increase in postprocedure VAS for those who had increase in pain was 34.3% and 31.7% for the MPA and DP group, respectively with no statistically significant difference noted (P = 0.8657). Review of electronic medical records showed no change in pain medication prescribed, emergency room visits for pain, or any new treatments for pain in either group. No complications were reported by patients on nursing follow-up or seen in review of medical records including new neurological symptoms or new areas of pain. CONCLUSIONS Nonparticulate DP seems to be close to the safety and effectiveness of particulate MPA in the treatment of lumbar radiculopathy. There is, however, a statistically nonsignificant trend toward less pain relief and shorter duration of action that may be clarified in a larger and longer duration study.